1. Field of the Invention
The present invention relates generally to systems and methods for locating microchannel positions, and more particularly for optically locating microchannel positions as part of a scanning DeoxyriboNucleic Acid (DNA) sequencer.
2. Discussion of Background Art
DNA sequencing is a technique used in conjunction with a national plan to decode the human genome in as little time as possible. The human genome is a very complex structure containing about three billion nucleic acid "base-pairs." Current DNA sequencing techniques involve placing DNA fragments onto a slab gel and separating the fragments so that base-pair information can be determined. Electrophoresis is a common technique used to separate the base-pair fragments from each other. The base-pairs can then be identified by various optical techniques that involve collecting a series of data points across the slab gel.
In efforts to speed up base-pair identification glass plates, having a set of microchannels, enable separation of several groups of DNA fragments in parallel. This technique requires collection of a very large number of optical measurement. Twelve-hundred to three-thousand data points may be taken during a single scan across such glass plates. A total amount of data taken for the entire glass plate may run in the one to eight gigabyte range.
Due to the large amount of data involved, modern DNA sequencers employ scanning devices and computers to collect the data. However, when the microchannel plates are not placed in their holders the same way each time, or plates with different microchannel formats are used, the computer controlled scanning devices will not work as intended. Furthermore, motors which drive the sequencer scanning devices often vary in speed and suffer from hysteresis, preventing accurate motor positioning during a scan. All of these effects hinder test result reproducibility, and limit efforts to reduce the amount of data collected.
In response to the concerns discussed above, what is needed is a system and method for optically locating a microchannel position that overcomes the problems of the prior art.